Field of Invention
The present invention relates to an epoxy mortar material for a bridge expansion joint structure and a construction method thereof, which belongs to a technical field of building materials.
Description of Related Arts
The bridge expansion joint structure is an important part of bridge engineering. Its construction technology is a very critical process in bridge construction and a very important part which affects the quality of the bridge. The quality of the joint structure has an impact on the overall bridge connection, and causes a great impact on vehicles and car jumping, thereby resulting in traffic accidents.
Currently, during the construction of the bridge expansion joint structure, it is needed for pre-embedded reinforcements to be set, prefabricated steel sections and pre-embedded reinforcements are welded with each other, and then the cement concrete is poured into the grooves at two sides of the bridge expansion joint structure. The intrinsic structural strength of the bridge expansion joint structure is low and easy to be affected by outside temperature changes and concrete shrinkage; and the deformation of the bridge deck produces a greater stress at the expansion joint structure, due to the concrete belongs to the rigid material, the expansion joint structure is easy to be damaged. Simultaneously, due to long curing time and hard removing of the concrete, the construction of the damaged expansion joint structure is complicated and time-consuming.
China Patent CN103387353A, published on Nov. 13, 2013 and titled as “Flexible concrete for rapidly repairing expansion joint structure”, provides a flexible concrete for rapidly repairing an expansion joint structure, wherein: the flexible concrete comprises raw materials A, B and C with a mass ratio of 1:(1-2.5):(8-18); the raw material A is isocyanate or pre-polymer; an ingredient of the raw material B comprises polyhydric alcohol, plasticizer, chain extender, catalyst, filler, antioxidant, defoamer, coupling agent and pigment with a mass ratio of (100-105):(4-30):(5-20):(0.01-1):(20-100):(0-3):(0-3):(0-30):(0-20); an ingredient of the raw material C comprises aggregate. Difference between the above China Patent and the present invention are as follows.
(1) The ingredient of the raw material A is isocyanate or pre-polymers thereof.
(2) The ingredient of the raw material B comprises polyhydric alcohol, plasticizer, chain extender, catalyst, filler, antioxidant, defoamer, coupling agent and pigment with a mass ratio of (100-105):(4-30):(5-20):(0.01-1):(20-100):(0-3):(0-3):(0-30):(0-20).
The isocyanate or pre-polymers thereof, adopted by the above China Patent, have severe toxicity and strong irritation; once contacting therewith, other materials except stainless steel, nickel, glass and ceramic have the risk of corrosion and produce exothermic reaction; furthermore, while being repairing, the expansion joint structure is easy to be affected on existing material performances, and health hazards are brought to construction workers.
China Patent CN103964748A, published on Aug. 6, 2014 and titled as “Rapid repairing material for expansion joint structure and preparation method thereof”, provides a rapid repairing material for an expansion joint structure and a preparation method thereof, wherein: the rapid repairing material comprises components A, B and C; an ingredient of the component A comprises epoxy resin, reactive diluent and filler with a mass ratio of 100:(10-30):(5-40); an ingredient of the component B comprises curing agent and ultraviolet absorber with a mass ratio of (50-100):(0.1-3); an ingredient of the component C comprises aggregate; a mass ratio range of the component C to a sum of the components A and B is (3:1)-(8:1). Raw materials of the components A, B and C are respectively as follows.
(1) The reactive diluent is cardanol glycidyl ether.
(2) The filler is diatomaceous earth or activated silicon powders.
(3) The curing agent is phenolic amine.
(4) The ultraviolet absorber is the benzotriazole compound.
(5) The aggregate is the high-temperature calcined wear-resistant stone with a particle size of 0.6 mm-3.3 mm.
The above China Patent adopts the phenolic amine curing agent which has big brittleness; the flexibility of the rapid repairing material, provided by the above China Patent, is only adjusted by the reactive diluent cardanol glycidyl ether; the use of less reactive diluent results in insufficient flexibility of the rapid repairing material, and the use of more reactive diluent results in low bond strength thereof, so that the curing time thereof is increased, thus the rapid repairing material is not suitable for practical application.
China Patent CN103980584A, titled as “Pouring material for bridge expansion joint transition zone and its preparation method and construction technology”, discloses a pouring material for a bridge expansion joint transition zone and its preparation method and construction technology, wherein: the pouring material comprises components A, B and C; an ingredient of the component A comprises epoxy resin, epoxy reactive diluent, superfine waste rubber powders, defoamer, and dispersant with a mass ratio of 100:(0-20):(10-50):(0.1-0.3):(0.1-0.3); an ingredient of the component B comprises curing agent, curing catalyst, and coupling agent with a mass ratio of 100:(0-10):(0.5-2); an ingredient of the component C comprises waste rubber particles, waste rubber powders and whiskers with a mass ratio of 100:(200-400):(10-30). Differences between the above China Patent and the present invention are as follows.
(1) The curing agent is one or more members selected from a group consisting of polyamide, fatty amine, alicyclic amine, aromatic amine, phenolic amine and modified products thereof;
(2) Black rubber particles and black rubber powders are adopted;
(3) Calcium sulfate whiskers with an average diameter of 1-8 μm and an average length of 50-200 μm are adopted.
The curing agent in the above China Patent, is one or more members selected from a group consisting of polyamide, fatty amine, alicyclic amine, aromatic amine, phenolic amine and modified products thereof, the curing agent has large brittleness and is easy to be cracked; the filler is mainly the black rubber particles and the black rubber powders, in spite that the rubber has a certain flexible for absorbing impact stress to a certain extent, the filler has low hardness, is easy to aging and not wear resistant; the pouring material, provided by the present invention, is directly poured into an installation position of the original expansion joint structure for forming a seamless expansion joint structure. The seamless expansion joint structure is an absolute elastic body, brittle and poor in impact resistance; after being used for a long time, it forms a bump, thereby bring inconveniences to passing vehicles.
Furthermore, the whiskers in the filler have the average diameter of 1-8 μm and the average length of 50-200 μm. Because the particles are very small, the mixed rubber solution is not easy to bond with the rubber, so that it is prone to result in uneven local mixing. In conclusion, the pouring material provided by the above China Patent has unstable material performance and short service life, and still needs to be improved and perfected in the actual use.